JP3020195B2 - Pallet changer for electric discharge machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pallet changing device for an electric discharge machine, and more particularly to an electric discharge machine in which a large amount of machining fluid is used or a pallet is immersed in machining fluid for machining. The present invention relates to a pallet changing device of an electric discharge machine provided with a shielding or wiping means on a pallet or a table side so as to avoid an operation failure and a decrease in accuracy due to the attachment of a foreign substance such as a machining fluid or machining chips (chips) to a clamping means.

[0002]

2. Description of the Related Art When machining a workpiece by immersing a pallet in a machining fluid with an electric discharge machine, the pallet is replaced by a pallet changing device after removing the machining fluid. The working fluid containing the chips falls into the clamping means arranged on the table and adheres to the positioning cone surface, thereby reducing the positioning accuracy of the pallet in the next step or shortening the service life of the clamping means. Therefore, in order to solve the problems at the time of this type of pallet replacement, the present applicant unclamps a pallet mounted on a table and lifts it with a pallet magazine or a transfer arm of a carrier when loading and unloading a pallet. When the pallet is carried in and out in the horizontal direction with the shielding member inserted and shielded between the clamp means and the bottom of the pallet, it is necessary to prevent the machining liquid containing chips from falling from the pallet into the clamp means. A pallet changing device for an electric discharge machine (see Utility Model Registration Application No. 72847 in 1993) equipped with a shielding means for preventing the occurrence of a pallet was developed. However, the above device
Demonstrated to have satisfactory properties in terms of purpose and effect, but the required actuators, control means, and other mechanisms are slightly more complicated, and additional space is required to install shielding means And the like, which is inconvenient in terms of the cost of the electric discharge machine and the arrangement of the machine.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a device,
An object of the present invention is to provide a pallet changing device for an electric discharge machine, which has a reliable operation, is simple and compact in terms of configuration and installation space, and is provided with a means for preventing a machining fluid including a chip from dropping to a clamping means. Aim.

[0004]

In order to achieve the above-mentioned object, the present invention has the following components. (1) When the pallet is reciprocated between a table provided with a clamping means for mounting the pallet and a pallet stocker, the machining liquid adhered to the pallet is prevented from dropping into the clamping means. In a pallet changing device of an electric discharge machine provided with a fall prevention means, the machining liquid fall prevention means is mounted on a bottom surface of the pallet and has a mountain-like or single-flow roof-like thin plate shape having a ridge parallel to a conveying direction of the pallet. When the pallet is mounted on the table, the cover member is provided at least from the clamping means to the end face position of the pallet on the opposite side of the pallet stocker, and sets the both-side eaves edge position to the clamping means. A pallet changing device of an electric discharge machine formed so as to extend outside the outer wall of the pallet.

(2) When the pallet is reciprocated between a pallet stocker and a table provided with a clamp for mounting the pallet, the processing liquid attached to the pallet is prevented from falling into the clamp. In a pallet changing device of an electric discharge machine provided with a machining fluid drop prevention means, the machining fluid fall prevention means is a wiper device arranged on an upper surface of the table opposite to the pallet stocker with respect to the clamping means, The wiper device is, when the pallet is mounted on the table, a semicircular wiper member surrounding a peripheral wall of the outer wall of the clamping means opposite to the pallet stocker, and the wiper device is attached to the table, and the pallet is mounted on the table. When transported from the table to the pallet stocker, the wiper member is moved to the bottom of the pallet. Discharge machine pallet exchange apparatus composed of a spring member for pressing the.

[0006]

When the pallet is exchanged by the pallet exchange device (P / C), as shown in FIG. 6, (1) after the electric discharge machining is completed and the machining fluid is discharged from the machining tank, the machining tank frame is lowered. Start pallet change. (2) The exchanging arm of the pallet exchanging device is advanced on the table (in the X-axis direction). (3) Unclamp the pallet mounted on the clamping means on the table. (4) The exchange arm of the pallet exchange device is inserted between the pallet and the table to hold the pallet, the exchange arm is raised (in the Z-axis direction), and a gap is provided between the pallet and the table. In inserting the exchange arm between the pallet and the table, the exchange arm does not interfere with the mountain-shaped cover member attached to the bottom surface of the pallet or the wiper member arranged on the table in any process.

(5) The processing liquid attached to the pallet and the chevron-shaped thin plate-like cover member flows along the front and back surfaces of the chevron, and falls from both side eaves to the outside of the clamping means arranged on the table, thereby causing The machining liquid attached to the pallet and the chevron-shaped thin cover member is prevented from dropping and adhering into the clamping means. (6) Even when the exchange arm is retracted (in the X-axis direction) and the processed pallet is carried out to the pallet stocker, the mountain-shaped thin plate-like cover member attached to the pallet always covers the upper surface of the clamp means arranged on the table. Therefore, during the movement of the pallet, the processing liquid attached to the pallet and the mountain-shaped cover member does not fall into the clamp means. (7) Alternatively, the wiper member pressing the pallet bottom opposite to the pallet stocker wipes out the working fluid attached to the pallet bottom as the pallet is conveyed.
Since the working fluid above the clamping means is removed, the working fluid attached to the bottom of the pallet does not fall into the clamping means during the movement of the pallet. In addition, since the wiper member does not protrude above or inside the clamp means including the displaced position, even if the machining liquid attached to the wiper member falls to the table side, it may fall outside the clamp means. However, it does not adhere to the clamping means.

(8) The exchange arm is retracted (in the X-axis direction), and the processed pallet is moved to the pallet stocker. (9) The replacement arm is lowered (in the Z-axis direction), and the processed pallet is placed on the pallet stocker. (10) On the pallet stocker, retract the exchange arm to the home position and index a new pallet to the exchange position. (11) The exchange arm is advanced (X-axis direction) to the indexed pallet. (12) While holding the pallet, the exchange arm is raised (Z-axis direction), and then advanced (X-axis direction) to just above the clamping means on the table. The mountain-shaped thin plate-like cover member attached to the bottom surface of the pallet or the wiper member provided on the table does not hinder the movement of the pallet. (13) Lower the exchange arm (in the Z-axis direction), set a new pallet on the clamp, and operate the clamp. Accordingly, the position of the wiper member is displaced against the bias of the spring, and does not hinder the positioning and mounting of the pallet on the chuck base. (14) Retract the exchange arm of the pallet exchange device to the home position (X-axis direction).

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pallet changing apparatus according to the present invention will be described below with reference to the drawings. The members constituting this embodiment are within the technical level in the industry at the time of filing the present invention. Since various types can be adopted, the gist of the present invention should not be interpreted by limiting the gist of the present invention based only on the configuration of the embodiment described below without showing a special reason.

FIG. 6 is an overall front view of an electric discharge machine equipped with the pallet changing device of the present invention. EDM table 1 is surrounded by machining tank 3 for lifting and sliding, Ji catcher Kkubesu 7 for mounting a pallet 5 is placed on the upper surface thereof. The table 1 is mounted on a bed 11, and a column 9 is erected on the bed 11 behind the table 1 so as to be movable in the X-axis direction. The head 15 is provided so as to be movable in the Z-axis direction and opposed to the chuck base 7 arranged on the table 1. The work mounted on the pallet 5 mounted on the chuck base 7 is immersed in a processing liquid filled in the processing tank 3 indicated by a virtual line, subjected to electric discharge machining by the processing electrode mounted on the electrode head 17, and finished processing. Thereafter, the processing liquid is discharged from the processing tank 3 and the processing tank 3 is lowered to the position shown by the solid line, and then pallet replacement is started. When changing the pallet, the pallet 5 to which the machining fluid has adhered
Is conveyed to the pallet stocker 19 from the clamping means arranged on the table 1. In addition, a pallet changing device is provided adjacent to the electric discharge machine,
The pallet stocker base 21 on which the pallet stocker 19 is arranged at the same height and the support 23 attached to the pallet stocker base 21 are guided by the vertical guide 25 and are movable in the Z-axis direction.
The slider 33 is guided by horizontal guide rails 27 attached to a slider unit 29 provided with the slider 7 and slides in the X-axis direction. The slider 33 is held by the slider 33, and can reciprocate between the pallet stocker 19 and the table 1. And a pallet exchange arm 31 provided in the pallet.

FIG. 1 is an enlarged perspective view of the structure of an embodiment including a pallet used in a pallet changing device of an electric discharge machine according to the present invention and a machining liquid drop prevention member applied to a clamping means. FIG. 2B is a side sectional view when the pallet is clamped on a table, and FIG. 2B is a side sectional view when the pallet is unclamped and then raised from the table in the Z-axis direction. FIG. 3 is a front view when the pallet is clamped on a table in FIG. 2A, that is, an X-axis direction parallel to the upper surface of the pallet is a pallet conveyance. A Z-axis direction arrow perpendicular to the direction indicates a pallet attaching / detaching direction.

Referring to FIG. 1, at a predetermined position on the table 1, a recess having a positioning surface 39 and a chuck 41 are provided.
A positioning plate 35 and a pull stud 37 provided on the bottom surface of the pallet 5
And the pallet 5 is mounted. A chuck seal 43 is provided on the peripheral edge of the upper surface of the chuck base 7 to seal the chuck base 7 when the pallet 5 is clamped on the table 1, and a machining liquid immersed in the processing tank 3 is used for electric discharge machining. 7 is prevented from entering. Further, a positioning plate 35, a pull stud 37, and four positioning pins 45 are attached to predetermined positions of the bottom surface of the pallet 5 indicated by phantom lines facing the chuck base 7. When the pallet 5 is clamped to the chuck base 7, the positioning plate 35 is fitted to the upper portion of the chuck base 7 to perform horizontal positioning, and the four positioning pins are used.
The pull stud 37 is pulled into the chuck 41 to perform the positioning in the up and down direction by contacting the positioning surface 39 with the positioning surface 39. The direction of the arrow indicated parallel to one side edge of the pallet 5 is the X-axis direction, and the direction of conveyance of the pallet 5 at the time of pallet replacement. Shows the direction in which the pallet 5 is attached to and detached from the table 1.

At the bottom of the pallet 5, a punching portion 47 is formed to avoid the chuck base 7 when clamping onto the table 1, and a ridge passing through the center of the positioning plate 35 and parallel to the direction of transport of the pallet 5 (X axis). A chevron-shaped thin cover 51 having 49 is attached via a ridge 49 portion. The position of the end face of the cover 51 is required to be at least slightly wider than the end face of the pallet 5 opposite to the pallet stocker 19, but in practice, it should be the same as the length of the pallet 5 in the X-axis direction. I have. Further, the edges of both eaves 53 of the cover 51 need to extend to the outside of the peripheral wall of the chuck base 7. Therefore, after the electric discharge machining, the machining fluid adhering to the bottom surface of the pallet 5 falls on the ridge 49 of the cover 51 and flows along the inclined surface, and the chuck bases arranged on the table 1 from the edges of both eaves 53 respectively. 7 falls outside. Further, when the pallet 5 is transported, the cover 51 always covers the upper surface of the chuck base 7, so that there is no possibility that the working liquid attached to the bottom surface of the pallet 5 falls into the chuck base 7 arranged on the table 1. Further, since the edge of the eaves 53 on the inclined surface of the cover 51 extends to the outside of the chuck base 7, the processing liquid attached to the bottom surface of the pallet 5 and the inclined surface of the chevron cover 51 flows along the front and back inclined surfaces of the cover 51. Since the pallet 5 is dropped on the table 1 from the edge 53, the working liquid does not fall into the chuck base 7 disposed on the table even if the pallet 5 is displaced in the Z-axis direction.

After lifting the pallet 5 in the Z-axis direction,
Even when the pallet 5 is translated in the axial direction, the cover 51 attached to the pallet 5 bottom always exists between the pallet 5 bottom and the chuck base 7. Flows along the inclined surface of the front and back surfaces and falls on the table 1 from the edge of the eaves 53, so that the working liquid does not fall into the chuck base 7 arranged on the table 1. Therefore, there is no possibility that the positioning accuracy and the seating accuracy of the pallet 5 with respect to the chuck base 7 on the table 1 are reduced. When the length of the cover 51 in the X-axis direction is the same as that of the pallet 5 and extends to the same end, the transport direction of the pallet 5 in the X-axis direction may be either left or right. In the case of the present embodiment, when considering the flow path of the machining liquid adhering to the pallet 5 and the cover 51 in the chevron-shaped thin plate-shaped cover 51, the required action and effect can be obtained even if the cover is clogged, even if it has a single-flow roof shape. Play. At this time, the cover must be provided with a hole 47 for escape to the chuck base 7 arranged on the table 1. In addition, the projected area of the cover with respect to the plane is the same as that of the above embodiment.

FIGS. 4 and 5 show another embodiment of the apparatus of the present invention. FIG. 4 (a) shows a state where the pallet is clamped on a table, and FIG. 4 (b) shows a state after the pallet is unclamped. And front sectional views when the table is raised in the Z-axis direction from above the table. FIG. 5 is a plan view of the wiper device including the clamp means, as viewed from the arrow B in FIG. 4B. The configuration and operation of the table 1, the pallet 5 and the clamping means of this embodiment are basically the same as those of the first embodiment described above.

Referring to FIG. 4, a plurality of leaf springs 57 surround a peripheral wall of the chuck base 7 disposed on the table 1 on the opposite side of the pallet stocker 19 and have a semi-circular planar shape. It is attached to the bracket 59 arranged on the table 1 by using. As shown in FIG. 4 (b), even when the pallet 5 is raised in the Z-axis direction, the upper end edge of the wiper blade 55 uniformly presses the bottom surface of the pallet 5 as shown in FIG. When the pallet 5 is transported in the X-axis direction, the wiper blade 55 wipes off the processing liquid attached to the bottom surface of the pallet 5. As a result, when the machined pallet is replaced after the electric discharge machining, the machining fluid adhering to the bottom surface of the pallet 5 is removed from the table 1.
There is no danger of falling into the upper chuck base 7 and lowering the positioning accuracy and seating accuracy of the pallet 5. However, when a new pallet 5 is loaded onto the table 1 from the pallet stocker 19, the position of the pallet 5 in the Z-axis direction is set slightly higher than the upper edge of the wiper blade 55 to which the strongest urging force is applied by the leaf spring 57. Otherwise, there is a risk that the upper end edge of the wiper blade 55 arranged on the table 1 may abut on the end face of the pallet 5 in the traveling direction.

Further, as shown in FIG.
7, when the pallet 5 is clamped on the table 1, the wiper blade 55 bends so as to move in parallel to the position close to the peripheral wall of the chuck base 7 and retreats so that the wiper blade 55 is supported. It is desirable that a pair of leaf springs 57 be applied to the upper and lower sides of the wiper blade 55, respectively. Furthermore, as shown in FIG. 5, the planar shape of the wiper blade 55 has its both end positions in semicircular surrounding the chuck base 7 peripheral wall is located outside the outer diameter of the tea Tsu Kubesu 7, and the chuck base 7 Is provided on the side opposite to the pallet stocker 19. In the case of this embodiment, the wiper blade 55 is also
Is supported by a leaf spring 57 disposed on the opposite side of the pallet stocker 19, so that the pallet 5 descends in the Z-axis direction and approaches the table 1. Since the wiper blade 55 approaches and moves to the side wall 7, the plane shape of the wiper blade 55 must be determined and arranged so that the wiper blade 55 does not interfere with the side wall of the chuck base 7.
If the wiper blade 55 is provided so as to be movable only in the Z-axis direction and is urged in the same direction, the distance between the wiper blade 55 and the chuck base 7 in FIG. 5 can be reduced.

[0018]

The present invention has the above-described structure and operation. (1) When the pallet is unclamped and reciprocated to the pallet stocker, it is attached to the pallet by a simple mechanism. The working fluid including the chips can be prevented from dropping on the positioning surface or the like provided on the clamping means on the table, and the positioning accuracy and seating accuracy of the pallet are improved. (2) The service life of the clamping means is extended,
Seating accuracy can be maintained for a long time. (3) A simple and compact structure that does not impair the characteristics of the means for preventing machining fluid from dropping, saves space for arranging EDMs,
Contribute to cost reduction. For example, a special action and effect that cannot be expected from the pallet changing device of the electric discharge machine conventionally used are exhibited.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of a pallet of a pallet changing device of the present invention.

FIG. 2 is a side sectional view showing the vicinity of a chuck base when the apparatus is pallet clamped and unclamped.

FIG. 3 is a view taken in the direction of arrow A in FIG.

FIG. 4 is a front sectional view showing the vicinity of a chuck base when a pallet is clamped and unclamped according to another embodiment of the pallet changing device of the present invention.

FIG. 5 is a view as seen from the arrow B in FIG. 4 (b).

FIG. 6 is an overall front view of an electric discharge machine equipped with the pallet changing device of the present invention.

[Explanation of symbols]

 1 Table 45 Positioning pin 5 Pallet 47 Pull-out part 7 Chuck base 49 Edge 19 Pallet stocker 51 Cover 35 Positioning plate 53 Eave 37 Pull stud 55 Wiper blade 39 Positioning surface 57 Leaf spring 41 Chuck 59 Bracket 43 Chuck seal

Claims (2)

(57) [Claims] When the pallet is reciprocated between a table provided with a clamping means for mounting the pallet and a pallet stocker, the processing liquid attached to the pallet is prevented from falling into the clamping means. In a pallet changing device of an electric discharge machine provided with a machining fluid drop prevention means, the machining fluid fall prevention means is mounted on a bottom surface of the pallet and has a mountain shape or a single-flow roof shape having a ridge parallel to a conveying direction of the pallet. When the pallet is mounted on the table, the cover member is provided at least from the clamping means to the end face position of the pallet on the opposite side of the pallet stocker. A pallet for an electric discharge machine characterized by being formed so as to extend outside the outer wall of the clamping means. Exchange equipment. 2. When the pallet is reciprocated between a table provided with a clamp means for mounting the pallet and a pallet stocker, the processing liquid attached to the pallet does not fall into the clamp means. In a pallet changing device of an electric discharge machine provided with a machining fluid drop prevention means, the machining fluid fall prevention means is a wiper device arranged on an upper surface of the table opposite to the pallet stocker with respect to the clamping means, When the pallet is mounted on the table, the wiper device has a semicircular wiper member surrounding a peripheral wall of the outer wall of the clamping means opposite to the pallet stocker, and is attached to the table, and the pallet is attached to the table. When the wiper member is transported from the pallet stocker to the bottom of the pallet, Discharge machine pallet exchanging apparatus which is characterized in that it is constituted by a spring member in contact.